It happened with plastics and now it's happening with flame retardants. Older chemicals that were thought to pose a health hazard were replaced by newer chemicals that were supposed to be safer. But now these chemicals are causing safety concerns of their own.

Newer flame retardants called organophosphates have been replacing older ones for several years. They're found in furniture, electronics and children's sleepwear and other products for kids. The new retardants began replacing the older variety because of mounting health concerns. Particularly troubling was evidence that exposure to the older flame retardants put children at risk for reduced IQ, attention and other developmental problems. Now it's beginning to look like the new flame retardants can cause similar damage.

Much of the information showing how toxic the older flame retardants are did not emerge until after they began to be regulated.

Researchers conducted a literature review that compared published findings on the potential health hazards of newer and older (PBDE) flame retardants. The team concluded that the newer ones have similar potential for harm.

Much, but not all, of the evidence comes from laboratory tests and animal studies. One study that did look at women suggests that newer flame retardants may cause fertility problems for them.

The precise amount of harm these chemicals can do has not yet been well established, but the researchers point out that obtaining enough scientific evidence of toxicity to cause regulation of these flame retardants could take years — much of the information showing how toxic the older flame retardants are did not emerge until after they began to be regulated.

Lessons Not Learned
It's a scenario that has happened time and again.

Consider BPA. The Food and Drug Administration insisted for many years that it posed no danger to humans. Eventually enough evidence emerged that it was hazardous to children so the chemical was banned from baby bottles and sippy cups in 2012.

Then there's the case of phthalates, chemicals added to plastics to make them softer and more flexible. Health concerns led to the removal of one called DEHP, and it was replaced with two newer chemicals, both of which have since raised health concerns of their own.

Try to keep your exposure low. Reading labels when buying furniture can help.

These are just two illustrations of how seemingly harmless chemicals later turn out to be anything but innocuous. That's why replacing suspect chemicals with other largely untested chemicals has caused so many problems. As Indiana University researcher and study co-author, Marta Venier, puts it: “These results show the danger of the whack-a-mole approach to chemical policy. When manufacturers have to stop using a toxic chemical, they often replace it with a similar chemical with similar harms. In the case of flame retardants, we're jumping out of the frying pan and into the fire.”

What is needed, Venier and her colleagues believe, is out-of-the box thinking. One example they cite is a TV manufacturer who moved the power supply from the inside to the outside, substantially reducing the amount of flame retardant required in these TVs. The group also endorses a greater reliance on materials that are more fire resistant than those currently in use.

On a personal level, it is hard to avoid exposure to flame retardants, but there are ways you can limit it. Reading labels when buying furniture can help because many now say whether or not the furniture contains these chemicals. A longstanding Duke University program will analyze the contents of the foam in furniture that you currently own if you send in a sample. It is possible to get the foam in furniture and cushions replaced with retardant-free material. And of course, sealing up holes in furniture that allow foam to escape can also help.

The study appears in Environmental Science & Technology Letters.